Envelope sealing machine



Dec. 24, 1940. A, RAND 2,226,411

ENVELOPE SEALING MACHINE Filed Dec. 8, 1939 4 Sheets-Sheet 1 In van in, Leon ar-d/llexanJerRand T A ltor ney Dec. 24, 1940. 1.. A. RAND ENVELOPE SEALING MACHINE Filed Dc. 8, 1939 4 Sheets-Sheet 2 Inocnlm Leonardfllexandepjf Alto my Dec. 24, 1940. 1.. A. RAND ENVELOPE SEALING MACHINE 4 Sheets-Sheet 3 Filed Dec.

F i'g. 4.

In ocular I; eonarciifl'lexander-fiand' Dec. 24, 1940. L. A. RAND ENVELOPE SEALING MACHINE Filed Dec. 8, 1939 4 Sheets-Sheet 4 I n vcntnr Rand Leonardfllexandr Patented Dec. 24-, 1940 ENVELOPE SEALING MACHINE Leonard Alexander Rand, London, England, as-

signor .of one-half to The International Coin Counting Machine Comp England Application December 8, 1939, Serial No.

In Great Britain July 14, 1939 17 Claims.

In a machine for sealing envelopes, the envelopes are fed successively to devices for raising the flaps, moistening the adhesive on the flaps and pressing the moistened flaps against the f bodies of the envelopes. r

An object of the present invention is to provide certain improvements in envelope sealing machines of this: kind.

One object of the invention is to provide improved means for feeding the bottom one of a pile of envelopes to flap raising and moistening devices of an envelope sealing machine whilst restraining the envelopes above the bottom one.

y Such means may comprise a pairof endless belts adapted to engage the bottom envelope of a pile,

a pair of spring-pressed members bearing on the belts and a resilient stripper member between these spring pressed members bearing on a fixed member between the belts.

Another object of the invention is to provide improved means for closing the flap of the envelope smoothly onto the body. The envelope during its passage through the sealing mechanism is given a tendency to turn bodily towards example by driving means at top and bottom edges of the envelope arranged sothat the driving means at the top (flap) edge have a lower longitudinal speed than those at the bottom edge.

A' further object of the invention is to provide an envelope sealing machine having a flap mois-- toning device fed -with-water from a reservoir in whichthe water is heated during its passage from the reservoir to the flap moistening device.

Yet another object of the invention. is to provide an envelope sealing machine'suitablefor sealing envelopes of various widths, lengths and thicknesses. With this object in view, the flap opening and moistening devices are arranged on a cantilever arm which is substantially unobstructed on its under surface and which is pivotable about a horizontal axis so that it can. rise to allow envelopes of various'thicknesses to pass.

The flap opening and moistening devices may the side of the machine nearest the flap, for

be supported from the end of this arm by a any Limited, London,

In the drawings: Fig. 1 is a plan view of a specific form of envelope sealing machine,

Fig. 2 is a cross-section on the line 24 of Fig. l with parts removed for the sake of clarity,

Fig. 3 isa diagram of the electrical connections,

Fig. 4 is asection of part of the machine on the line IV-IV of Fig. 2,

Fig. 5 is a section of the envelope moistening device taken on the line V-V of Fig. 1,

Fig. 6 is a view in. plan of part of the moistening device shown in Fig. 5,

line 8-8 of Fig.

Fig; 9 is a cross section taken on the line 9-9 of Fig 1.

Fig. 10 is a vertical section taken on the line Iii-l0 of Fig.4.

The envelopes pass through the machine shown in the. drawings, from the left hand side of Figs. 1 and 2 to the right hand side, and in the following description, terms are used stationed at the front and .back? and similar with reference to an. observer left hand side of Fig. 1 or 2 and looking in the direction in which the envelopes move.-

A hopper l in which the envelopes are placed in a pile is provided at the front end of the machine. 3 This hopper has an inclined front wall 2 (sloping downwardly and forwardly) which is adjustable lengthwiseof the machine and a depending rear wall 3 beneath which is a gap 4 through which the envelopes pass to flap-opening,

moistening' and One side wall other 6 is adjustabletowards it by sliding movement on? the-bar sealing mechanism. 5'o-f the hopper is fixed and the I so that the width of the hopper I maybe'adjusted to suit different widths of the envelope. 1 i

vThe envelopes are stacked in the hopper I one above the otherpwith their flaps in the closed position and facing upwardly. The front and side walls 2, 30f the hopper are adjusted so that the envelopes are inclined downwardlyat a small angle with their leading ends lower than their other ends,

these belts and the hopper.

The belts 8, 9

is fed forwardly by them out of are preferably of rubber and are belts.

The pulleys are prefer-ably formed with an annular recess on each side of a central pro-.

jecting rim l1 and the cross-section of the belts is such as to correspond with the rims of the pulleys as is shown clearly in Fig.

Mounted above each belt 8, 9 is a presser foot |8, I3 which presses the envelope on to the belt as it leaves the hopper. Each presser foot comprises a member pivoted about a spindle 26 supported in a position transversely of the belts from the fixed side wall 5 of the hopper and behind the rear wall 3 of the hopper. This member is curved so as to provide a foot portion 2| lying along the belt and. this portion 2| is concave on its underside so as to cover the width of the belt. A coil spring 22, fixed at one end to the presser foot E8, or l9 and anchored at the other presses the foot into contact with the envelope: and causes the latter to be gripped between' the belt and the foot. An adjustable set screw 23 carried by the presser foot abuts against a stop 24 to limit the pressure of the foot on the belt.

Between the two presser feet l8, l9is mounted a stripper member 25 of resilient material, such as rubber, the bottom edge of which, in the absence of an envelope, rests upon a lowermember 25 (preferably highly polished on its top surface) fixed between the two belts 8, 9. This lower member is preferably provided with ribs 21, 28 parallel to each side so as to provide spaced contacts with the stripper member 25. This arrangement prevents the passage of two envelopes together; the stripper member holding the top one of two envelopes which may have been fed together from the hopper whilst the belts engage frictionally with and move forward the bottom one of the two which slides freely over the highly polished surface of the lower member.

From the two feed belts 8, 9, the envelope is transferred to a belt 29 which carries it past the flap opening, moistening and sealing mechanism. This belt 29 is at the side of the machine and runs in the same direction as the two feed belts 8, 9. It runs around a pulley 30 mounted on the transverse driving shaft l3 of the feed belts and around a pulley 3| on a parallel shaft 32 at the far end of the machine. The driving pulley 36 of this belt 29 is of greater diameter than the coaxial driving pulleys |2 of the two feed belts 8, 9 so that, on leaving the feed belts the envelope is accelerated relatively to the succeeding one. A gap is thus left between successive envelopes as they pass through the machine.

The flap edge of the envelope is supported by the second belt 29 and its other edge is supported by rubber covered rollers 33, 34 which are mounted coaXially with the two pulleys 35, 3| respectively around which the second belt 29 passes. The supporting roller 34 towards the end of the machine is of somewhat greater diameter than is the belt 29 in passing round the pulley 3| so that there is a tendency for the envelope to be turned bodily towards the side of the machine nearest the flap edge of the envelope.

Just beyond the driving pulley of the second belt is a spring loaded plate 35 running along the side of the belt. This side plate 35 is pivotally supported from the end of an arm 60 which is urged by a spring 6| to a position in which the side plate 35 is pressed on to the belt 29. The face of the plate in contact with the belt is inclined so that it presses at an angle on the flap of the envelope thereby bending it and slightly opening the flap; as it is spring loaded and presses on the envelope it also gives an intermediate pull for short envelopes.

The flap opening and moistening devices are carried by an arm 36 pivoted at one end about a pin 31 at the side of the machine nearest the flap and extending transversely across the machine.

The axis of the pivot pin 31 is parallel to the direction of travel of the envelope so that this arm 36 can be lifted clear of the belt 29 and turned through about 180.

The flap opening and moistening devices are pivoted to the end of the arm 36. The end of this arm is bifurcated to provide a yoke 62 through the arms of which pivot pins 63 pass into the body of the flap-opening and moistening assembly. These pins 63 are arranged further from the hinge pin 31 than is the centre of gravity of the flap opening and moistening assembly so that the moistening device is biased downwardly tending to fall away from the arm 36. Excessive pivotal movement in this direction is prevented by a stop 64 (as shown, the end of the arm 36) and in the other direction by a stop 65 (as shown the under-surface of the arm 35) The position of the arm 36 can be adjusted by a screw 66 passing through the arm and bearing against a fixed abutment 61 (Fig. 5).

A flap opening member 36 is carried by the arm 36 and comprises a plate projecting towards the oncoming envelope. This plate has a front edge 39 which is shaped so as to pass between the body of the envelope and the flap when the latter is initially opened by operation of the plate 35, so that the flap is slightly raised relatively to the envelope and passes through an open ended slot 40 formed between a flap moistening device and a cover plate 68. In its passage through this slot 40, the flap is moistened so that adhesive thereon becomes sufiiciently tacky to adhere to the body of the envelope, thereby sealing it, when the envelope has passed the transverse arm 36.

A roller 4| is mounted beyond this arm and presses down on the envelope so as to close the flap against the body of the envelope. This closing roller 4| is mounted on one end of a pivoted arm 42 and its weight causes it to press down on the envelope sufficiently to ensure correct sealing.

The tendency of the envelope to turn towards the side, caused by the difference in peripheral speed of the belt 29 and the supporting roller 34 ensures that the flap will be pressed down smoothly on to the body of the envelope and buckling of the flap is avoided.

The flap moistening device comprises a wetting device 43 preferably one of which the surface may be kept wet by capillary action. The capillary device shown in the drawings is a felt pad but any equivalent device such as that shown in Fig. 7 comprising a hollow member 10 having a narrow slot 1| in its upper surface, may be used. The felt pad as shown is mounted in a shallow tray 44 supported beneath the pivoted arm 36. The top surface of the felt pad 43 formsthe lower side of the open ended slot 4-0 through which the envelope passes.

The tray 44 is supplied with water from a reservoir 45 which is carried on the pivoted arm 36 and which feeds water into the tray on the birdfountain principle so that the level of water in the tray 44 is maintained below the top of the pad 43. The reservoir 45 has a restricted neck 46 at its bottom which fits over a spigot 41 formed on the pivoted arm 36. A tube 48 passes through this spigot 41 so that its upper end opens into the reservoir 45' and its lower end opens into the tray 44 and determines the level of water therein.

By swinging the pivoted arm 36 over through about 180, the reservoir 45 is brought into. a position in which its neck 46 is uppermost. The reservoir can thus be removed and replaced whilst containing water without danger of spilling and without the use of special valves or the like to close the neck of the reservoir during its inversion.

Means are provided for heating the water which passes to the tray so that the adhesive on the envelope flap is moistened with warm water thereby making it possible to increase the rate of sealing without risk of the envelopes not being properly sealed. An electric resistance heater 49 surrounds the spigot 46 through which the water is fed, this heater being supplied with current through leads 50 passing along the pivoted arm 36 and looped near the pivot 31 to allow the arm to be moved. The heater may be connected in parallel with the motor which drives the machine. In order to concentrate the heat generated on the water being fed through the spigot 46, the heater is enclosed in heat insulating material 5! such as asbestos.

The heater is preferably of such rating as to bring the water rapidly to the desired temperature and means are provided to reduce the power taken by the heater after this temperature has been attained. A time switch 69 for example is arranged so as to insert, in. series with the heater, an additional resistance such as an electric lamp 58, after the machine has been. running for a predetermined time. This time switch 69, may for example, remove a short-circuit on the extra resistance 58 when it is opened after the predetermined time.

Other means may be adopted to reduce the power taken by the heater, for example. thermostatic devices operated by the temperature of the water.

Means are provided to prevent excessive vapour pressure in the tray. For this purpose, an aperture above the water level is sufiicient but it is preferred to conduct the exhaust vapour to the felt pad. Lying along one side of the felt pad 43 is a tube 52 having openings 53 directed on to the pad. This tube at its other end 54 opens into the water tray above the normal water level. Any steam which may be generated in the tray 44 is thus released from that end of the chamber adjacent to the tube 48 and is led to the felt pad to moisten it. Undesirably high vapour pressures in the tray are thus relieved through this tube.

A second tube 55 lying along the other side of the felt pad 43 and having openings 55 directed on to the pad, is curved to lie around the spigot 41 beneath the heater 49 and is connected to a passage 51 in the spigot which opens into the reservoir 45. Through this tube 55, water heated by the heater, is led to the extreme end of the pad which is thus kept moist throughout its length. This tube 55 also ensures that the level of the water in the second half of the tray (that is the part holding the felt pad) will be kept constant, and for this purpose may be advantageously incorporated in envelope sealing machines in which the water is not heated before passing to the pad.

An indicator lamp 59 may be connected across the heater to show visually that this is in use and this lamp 59 may be arranged in conjunction with the lamp 58 used to limit the power taken by the heater to indicate that the heater has been reduced in power.

It will be appreciated that the arrangement of the flap opening and moistening devices on the pivoted cantilever arm is such thatthis arm may be substantially flat and unobstructed on its lower surface, so that the machine may be used for envelopes of any normal size. The pivotal arr'angement of this arm also allows it to rise to accommodate itself to envelopes of varying thicknesses without special adjustment, the flap moistening device pivoting about the pins 62! so as to remain substantially horizontal, or, at least, so as to reduce the angle to which the device would otherwise be moved by a thicl: envelope.

It will be understood that the details of the exemplary machine described above may be modified without departure from the broader aspects of the invention which is not therefore restricted to or by such details.

I claim:

1. In a machine for sealing envelopes means for feeding the envelopes singly to flap moistening devices comprising an endless belt arranged to contact the bottom one of a pile of envelopes, a spring pressed member bearing on the belt beneath which the envelope is fed and stripping means comprising a fixed lower member and a resilient upper member between which the envelope is fed, said stripping means acting to prevent passage of more than the lowermost envelope of the pile. I

2. A machine for sealing envelopes comprising a hopper in which envelopes may be arranged in a pile, a pair of endless belts projecting into the bottom of the hopper, spring pressed members bearing on each belt, a fixed member mounted between the belts, a resilient member resting upon this member and flap opening and moistening means to which the bottom envelope of the pile,

is fed by the endless belt between the spring pressed members and the belt and between the fixedmember' andv the resilient member.

3. A machine as defined in claim 2 in which the fixed member and the resilient member are of such material that the friction between an envelope and the fixed member is less than that between an envelope and the resilient member.

4. A machine as defined in claim 2 in which the fixed member is ribbed parallel to the direction of the envelope through the machine to reduce the area of contact between the fixed member and an envelope.

5. In a machine for sealing envelopes, flap moistening means comprising a wetting device, a water reservoir, a conduit means for feeding water from the reservoir to the wetting device and means for heating the water during its passage through the conduit means to the pad.

6. In a machine for sealing envelopes, flapmoistening means comprising a tray, a wetting device fed from the tray, a reservoir for water, a feed tube projecting into the reservoir and opening above the bottom of the tray 50 as to feed water into the tray to a predetermined level and heating means surrounding the feed tube and adapted to heat the water fed to the tray.

'7. In an envelope sealing machine, flap-moistening means comprising a tray, a wetting device fed from the tray, a reservoir for water, a conduit member opening into the water reservoir and having a part arranged along the wetting device,

ting device and heating means arranged adjacent to this conduit so as to heat water passing therethrough from the reservoir to the wetting device.

8. An envelope sealing machine comprising means for feeding envelopes in succession through the machine, an arm pivoted at one side of the machine and movable from a position extending across the line of travel of the envelopes to a 10; position extending from the side of the machine,

a Wetting device mounted on the arm and forming on the underside of the arm one side of a slot through which the flap of the envelope may be fed, and a reservoir for water mounted on the arm with its open end directed downwardly, the

arrangement being such that When the arm is moved about its pivot to extend from the side of the machine, the water reservoir projects downwardly from the arm and may be removed.

9. In an envelope sealing machine, the combination of an arm pivoted at one side of the machine with a reservoir closed at the bottom and mounted on the arm so as to be movable with the arm from an inverted position in which 'it feeds water to flap moistening devices carried by the arm to a position in which it hangs downwardly from the arm and can be removed.

10. An envelope sealing machine comprising a flap opening and moistening device, flap sealing means, means for feeding the envelope past these sealing means and means tending to move the body of the envelope transversely in relation to the flap in a direction to close the flap smoothly on to the body of the envelope.

11. An envelope sealing machine comprising a flap opening and moistening device, flap sealing means, means for driving the envelope past the sealing means contacting the envelope towards its top edge and driving means contacting the envelope towards its bottom edge, these latter driving means having a higher longitudinal speed than those at the upper edge.

12. An envelope sealing machine comprising a flap opening and moistening device, an endless belt contacting the envelope towards its top edge, a roller mounted to rest on the endless belt beyond the flap opening and moistening device, and

' this part having openings directed on the weting and moistening devices, an endless belt ar ranged-to feed envelopes through the flap opening and moistening devices, and a plate mounted at the side of the endless belt and resiliently urged into contact with the belt, this plate being inclined at an angle to the surface of the belt so as to bend and slightly open the flap of an envelope carried by the belt.

15. In a machine for sealing envelopes, flap moistening means comprising an absorbent pad,

a Water reservoir, conduit means for feeding water from the reservoir to the absorbent pad, an electric heating device for heating the water during its passage through the conduit means to the pad and means for reducing the power to this heater after the water has been brought to f the desired temperature. I

16. Flap moistening means as defined in claim 15 comprising an electric resistance and a time switch arranged to place the resistance in series with the heating device after a predetermined r,-

interval.

17. An envelope sealing machine having flap opening and moistening devices pivotally connected at one end of an arm pivotally supported at its other end at one side of the machine and arranged so that when the cantilever arm is raised by a thick envelope to permit passage thereof, the flap opening and moistening devices move relatively to the arm to maintain their lever position.

LEONARD ALEXANDER RAND. 

